National population-based tuberculosis prevalence survey in Ghana, 2013.

BACKGROUND: The prevalence of tuberculosis (TB) disease is one of the three main indicators used to assess the epidemiological burden of TB and the impact change of TB control; the other two are incidence and mortality.OBJECTIVE: To estimate the prevalence of TB disease among adults in Ghana.METHODS: A nationally representative cross-sectional survey was conducted. Participants were screened for TB using interview and chest X-ray (CXR). For those participants with cough ≥2 weeks and/or abnormal CXR, spot and morning sputum specimens were collected and examined by smear microscopy and culture.RESULTS: The study revealed that the prevalence of smear-positive TB among adults (age ≥15 years) was 111 (95%CI 76-145) and that of bacteriologically confirmed TB was 356 (95%CI 288-425) per 100 000 population. Males and older people had a higher prevalence than their counterparts. The majority of TB cases were smear-negative and had an abnormal CXR without reported chronic cough.CONCLUSION: The survey revealed much higher TB disease burden than previously estimated. This implies that the programme needs more effort and resources to find undiagnosed and unreported cases. The higher proportion of smear-negative and asymptomatic TB cases suggests the need to revise the existing screening and diagnostic algorithms.

The first population-based national tuberculosis prevalence survey in Ethiopia, 2010-2011.

SETTING: Tuberculosis (TB) remains a major public health problem in Ethiopia. OBJECTIVE: To determine the prevalence of pulmonary TB among the general adult population aged ≥15 years in 2010-2011. METHOD A nationwide, cluster-sampled, stratified (urban/rural/pastoralist), cross-sectional survey was conducted in 85 selected clusters. All consenting participants were screened for TB using: 1) chest X-ray (CXR) and 2) an interview to screen for symptoms suggestive of TB disease. RESULT: Of 51,667 eligible individuals, 46,697 (90%) participated in the survey and completed at least the screening interview. CXR was performed among 46,548 (99.7%) participants. A total of 6080 (13%) participants were eligible for sputum examination. From the survey, it was estimated that in the national adult population 1) the prevalence of smear-positive TB was 108/100,000 (95%CI 73-143), and 2) that of bacteriologically confirmed TB was 277/100,000 (95%CI 208-347). CONCLUSION: We found that the TB burden was lower than previously thought, which may indicate better programme performance. However, a high proportion of TB among young persons suggests that TB is circulating in the community and that there is a need for more efforts to limit the spread of TB disease.

Epidemiological impact of mass tuberculosis screening: a 2-year follow-up after a national prevalence survey.

OBJECTIVE: To assess the epidemiological impact of mass tuberculosis (TB) screening in the community and the prognosis of bacteriologically negative individuals with abnormal findings on chest radiography (CXR). METHODS: A follow-up study consisting of two parts--a register match of notified TB cases with 22,160 participants in a national TB prevalence survey, and a repeat medical examination for the subjects of a prevalence survey with abnormal findings on CXR--was conducted 2 years after the prevalence survey in Cambodia. RESULTS: Thirty-four cases with new smear-positive TB were detected by register match, giving a standardised notification ratio of 0.38 (95%CI 0.27-0.52). An additional seven new smear-positive TB cases and 93 new smear-negative, culture-positive TB cases were detected by medical examination. The incidence rates of bacteriologically positive TB were 8.5% per year (95%CI 6.3-11.2) in cases with a CXR suggestive of active TB and 2.9% per year (95%CI 2.2-3.7) in those with a CXR with other abnormalities. CONCLUSIONS: Detection and treatment of smear-negative, culture-positive TB cases as well as smear-positive TB cases was associated with a rapid reduction in subsequent incidence of new smear-positive TB. Sputum culture-negative individuals with abnormal CXR findings are at a high risk of disease progression, and require follow-up and potentially preventive treatment.

Organisation of a tuberculosis prevalence survey.

Measuring tuberculosis (TB) prevalence trends provides information on progress towards the Millennium Development Goals. The World Health Organization recently published guidelines on assessing TB prevalence through population-based surveys. The current manuscript describes in detail the organisation of the field activities in such a survey. These activities need to be embedded in a strong organisational framework where the steering committee has the overall responsibility and the survey coordinator the day-to-day supervision. Field activities need to be tailored to the community, with respect to both time and place and direct involvement of community members. Frequent and well-described monitoring procedures need to be in place to be able to identify systematic and non-systematic errors at the earliest opportunity.

Tuberculosis prevalence surveys: rationale and cost.

This article is the first of the educational series 'Assessing tuberculosis (TB) prevalence through population-based surveys'. The series will give overall guidance in conducting cross-sectional surveys of pulmonary TB (PTB) disease. TB prevalence surveys are most valuable in areas where notification data obtained through routine surveillance are of unproven accuracy or incomplete, and in areas with an estimated prevalence of bacteriologically confirmed TB of more than 100 per 100,000 population. To embark on a TB prevalence survey requires commitment from the national TB programme, compliance in the study population, plus availability of trained staff and financial resources. The primary objective of TB prevalence surveys is to determine the prevalence of PTB in the general population aged >or=15 years. Limitations of TB prevalence surveys are their inability to assess regional or geographic differences in prevalence of TB, estimate the burden of childhood TB or estimate the prevalence of extra-pulmonary TB. The cost of a prevalence survey is typically US$ 4-15 per person surveyed, and up to US$ 25 per person with radiographic screening. A survey of 50,000 people, of limited precision, would typically cost US$ 200,000-1,250,000.

National HIV prevalence surveillance among TB patients through periodic surveys: experience in Cambodia.

SETTING: The National Tuberculosis Programme (NTP) in Cambodia, one of the countries most affected by tuberculosis (TB) and human immunodeficiency virus (HIV) infection in Asia. OBJECTIVE: To conduct national HIV prevalence surveillance among TB patients, to estimate HIV prevalence among TB patients and to determine the potential of the NTP as a source for antiretroviral treatment (ART) scale-up. DESIGN: Anonymous unlinked cross-sectional seroprevalence surveys including all TB patients registered by the NTP in January 2003 and January 2005. RESULTS: HIV prevalence among all TB patients fell from 11.8% in 2003 to 9.9% in 2005 (P < 0.05). In 2003 and 2005, respectively 265 and 261 TB patients were identified as HIV-positive in a given month. Among new smear-positive pulmonary TB patients, the prevalence dropped from 8.2% to 5.2% (P < 0.01). CONCLUSION: The two periodic surveys demonstrated a high prevalence of HIV among TB patients in Cambodia. However, the declining incidence of HIV from the late 1990s might now be reflected in the HIV prevalence among new smear-positive TB patients. The NTP is a potential source of ART if HIV counselling and testing are made more widely available to TB patients.

Measuring tuberculosis burden, trends, and the impact of control programmes.

The targets for tuberculosis control, framed within the United Nations' Millennium Development Goals, are to ensure that the incidence per head of tuberculosis is falling by 2015, and that the 1990 prevalence and mortality per head are halved by 2015. In monitoring progress in tuberculosis control, the ultimate aim for all countries is to count tuberculosis cases (incidence) accurately through routine surveillance. Disease prevalence surveys are costly and laborious, but give unbiased measures of tuberculosis burden and trends, and are justified in high-burden countries where many cases and deaths are missed by surveillance systems. Most countries in which tuberculosis is highly endemic do not yet have reliable death registration systems. Verbal autopsy, used in cause-of-death surveys, is an alternative, interim method of assessing tuberculosis mortality, but needs further validation. Although several new assays for Mycobacterium tuberculosis infection have recently been devised, the tuberculin skin test remains the only practical method of measuring infection in populations. However, this test typically has low specificity and is therefore best used comparatively to assess geographical and temporal variation in risk of infection. By 2015, every country should be able to assess progress in tuberculosis control by estimating the time trend in incidence, and the magnitude of reductions in either prevalence or deaths.

Performance of an interferon-gamma release assay for diagnosing latent tuberculosis infection in children.

Newly developed interferon-gamma release assays have become commercially available to detect tuberculosis (TB) infection in adults. However, little is known about their performance in children. We compared test results between the QuantiFERON-TB Gold test (QFT) and tuberculin skin test (TST) in young children living with pulmonary TB patients in Cambodia. Of 195 children tested with both QFT and TST, the TST-positive rate of 24% was significantly higher than the QFT-positive rate of 17%. The agreement between the test results was considerable (kappa-coefficient 0.63). Positive rates increased from 6% to 32% for QFT and from 15% to 43% for TST, according to the sputum smear grades of the index cases. The presence of Bacille Calmette-Guérin (BCG) scars did not significantly affect the results of TST or QFT in a logistic regression analysis. In conclusion, QFT can be a substitute for TST in detecting latent TB infection in childhood contacts aged

The national tuberculosis drug resistance survey in Cambodia, 2000-2001.

SETTING: Cambodia has a high incidence of tuberculosis (TB). Hospital-based DOTS was predominant throughout the country from 1994 to 2002. OBJECTIVES: To determine the prevalence of resistance to four major anti-tuberculosis drugs, isoniazid (INH), rifampicin (RMP), ethambutol (EMB) and streptomycin (SM), among new cases as a baseline before a new National Tuberculosis Programme strategy with decentralised ambulatory DOTS was widely implemented. DESIGN: A cluster sampling of TB diagnostic centres with probability proportional to the number of new cases in a diagnostic centre in 1999 was used. Intake of cases took place from October 2000 to April 2001. RESULTS: From 734 isolates collected, drug susceptibility test results were obtained for 638 new cases. The prevalence of resistance to any of four drugs was 10.1% (95%CI 7.7-13). Resistance to INH was 6.1% (95%CI 4.3-8.4) and resistance to RMP 0.6% (95%CI 0.2-1.6). No multidrug-resistant (MDR) case was found among the new cases (95%CI 0.0-0.6). Three of 96 previously treated cases had MDR (3.1%, 95%CI 1.0-9.0). CONCLUSION: The first survey indicates that the current prevalence of MDR is low. It is necessary to track resistance trends when restructuring a DOTS-based programme.

[Tuberculosis infection control practice in hospitals from the viewpoint of occupational health].

Several outbreaks of tuberculosis (TB) among health care workers were reported recently in Japan. To assess the current situation of TB infection control practice in hospitals in Japan from the viewpoint of occupational health, we carried out a cross sectional survey by mail-questionnaires. The questionnaires with closed and open-ended questions to ask situation of TB infection control program in hospital were mailed to 542 hospital chiefs in and around Tokyo, Kantoh district. 269 replies were received. We analyzed them especially focussing on the prevention of TB among health care workers. Out of 269 hospitals replied, 39 of them had wards and/or beds designated for tuberculosis patients, 223 did not have, and 7 were unknown. 102 (38.9%) had set written tuberculosis infection control programs or guidelines, only 21 (53.8%) have set them even in hospitals with TB beds. 110 (42.0%) hospitals had triage system for identifying patients with active TB in the outpatient setting. Although, most health care workers underwent annual health check programs including chest X-rays, only 67 (25.6%) of the hospitals provide tuberculin skin test to their new recruits. 165 (63.0%) of hospitals admit that undiagnosed patients with respiratory symptoms may stay with immuno-compromised patients in the same room. Since administrative management, staff education, environmental control in work place, personal infection control and individual health care should be carried out from the viewpoint of occupational health, we showed concrete steps of these in this paper. We recommend that a TB infection control manager in each hospital should be designated, and that TB infection control program and/or guideline should be made. Environmental control in work place to prevent infection should be more prioritized in Japan.

[Koch's phenomenon after BCG vaccination and the two-step tuberculin test in elementary school children].

In Japan, BCG vaccination, which covers more than 90% of infants, has been given according to the national immunization policy. Moreover, first-grade children in elementary school are screened with tuberculin skin test, and those who show negative reaction in the Japanese standard, i.e. size of erythema less than 10 mm, are re-vaccinated with BCG according to the Tuberculosis Prevention Law. However, since the incidence of tuberculosis among children below age 14 is as low as 1.5/100,000 in Japan, it is time to reconsider the BCG vaccination policy. As the first step to assess the efficiency of the present program, we observed the occurrence of Koch's phenomenon after BCG vaccination in elementary school children in Chiba City in 1995 and 1996, and we introduced the two-step tuberculin test to elementary school children in 1997. Among 180 BCG vaccinated children in 1995 and 1996, 168 (93.3%) had been vaccinated by 4-year of age. We could follow local reaction of BCG re-vaccination and observed Koch's phenomenon in 117 (69.6%, 95% C.I. of 62.7-76.6%). Among 92 tuberculin negative children in 1997, 85 (92.4%) had been vaccinated by 4-year of age. In the two-step tuberculin test program of 85 initial negative-reactors, 63 (74.1%, 95% C.I. of 64.8-83.4%) turned to positive by the second test. Those results suggest that more than 69% of tuberculin-negative school children who were vaccinated previously maintained immunity with BCG. Our studies raised a problem of the current BCG re-vaccination policy that depends on the result of tuberculin test. Due to the discrepancy between tuberculin allergy and immunity in tuberculosis, many school children may be given BCG vaccination unnecessarily. Taking into consideration the incidence of tuberculosis in children, discontinuation of BCG re-vaccination policy at elementary school entrance should be considered.

Feasibility study of a district tuberculosis control programme with an 8-month short-course chemotherapy regimen utilizing the integrated health service network under field conditions in Nepal.

SETTING: Tuberculosis in Nepal has not been controlled; there is an annual risk of infection of more than 2%, a cure rate of 30-40% and a casefinding rate of 40%. The necessity of a pilot programme with short-course chemotherapy that could be applied across the nation was discussed, and an operational research project utilizing the existing basic health service network was launched. OBJECTIVE: The main objective was to assess the feasibility of integrating a tuberculosis programme into the basic health services under various field conditions, and of introducing an 8-month short-course chemotherapy regimen instead of the 12-month standard regimen. DESIGN: A tuberculosis control programme package based on the current international strategy was introduced in Dhading and Chitawan districts (population 650,000) in 1990. The reported results were confirmed by central supervision and a follow-up study. RESULTS: 454 new smear-positive cases were found in the first year. 69% were cured and 9% completed their treatment. However an 85% completion rate could be expected from the results of the follow-up study. CONCLUSION: An integrated tuberculosis control programme with short-course chemotherapy is feasible. An adequate supply of drugs and supervision are vital components. The results showed the possibility of achieving the international target of an 85% cure rate and 70% detection, even within the constraints of the field conditions in Nepal.

[The isolation of nontuberculous mycobacteria and the pulmonary infections of nontuberculous mycobacteria in the general hospital].

In the past eight years, we experienced 94 cases of nontuberculous mycobacteria (NTM) isolation from the specimens of sputum, gastric juice, pleural fluid and fiberoptic bronchoscopic procedure at Chiba Kaihin Municipal Hospital. The species of NTM were M. avium complex (MAC) in 23, M. gordonae in 15, M. kansasii in 12, M. fortuitum in 8, M. chelonae in 7, etc.. The number of isolation of NTM has increased, and it is worthwhile to mention that it had exceeded the number of isolation of M. tuberculosis since 1991. We experienced 28 cases of pulmonary infections caused by NTM during the same period. Thirteen cases were by M. avium complex, 11 cases by M. kansasii, one case by MAC and M. kansasii, one case by M. chelonae and two cases by unidentified NTM. Pulmonary infections by NTM also gradually increased. Thirteen cases (46.4%) had underlying diseases in the respiratory system. Most of them were progressive diseases with cavities and were easily diagnosed by mycobacterial examinations of the specimens such as sputum or gastric juice. We were unable to diagnose 12 cases (42.9%) by mycobacterial examinations. Most of them had no underlying diseases and showed small lesions without cavitation on the chest X-ray. Eight cases were diagnosed by the histopathological examination of TBLB (transbronchial lung biopsy) specimens. In such cases, these procedures were also useful for the early diagnosis. This study indicated the increase of the isolation of NTM and the pulmonary infections by NTM. Once the infections are established, they are progressive, and the early diagnosis of these infections are thought to be important.

[Clinical evaluation of combined therapy of ceftazidime and tobramycin for intractable pulmonary infection mainly caused by Pseudomonas aeruginosa].

In an open, multicenter trial, we investigated the clinical efficacy of a combination therapy of ceftazidime (CAZ) and tobramycin (TOB) for intractable pulmonary infections mainly caused by Pseudomonas aeruginosa. Evaluated for the utility of the combination therapy were 33 cases with pneumonia (Group I: pneumonia caused by P. aeruginosa 15, Group II: pneumonia caused by other Gram-negative bacilli 4 and pneumonia which causative organism was not determined 14) and 23 cases with chronic respiratory tract infection caused by P. aeruginosa. The results obtained are summarized as follows. 1. In Group I pneumonia, included 11 severe cases and 4 moderate cases, with a mean age of 69.3 years. Significant underlying diseases were present in 14 out of the 15 (93.3%): they included 10 cases of pulmonary diseases and 4 cerebrovascular diseases. The overall efficacy rate in these cases was 60.0%: but the efficacy rate in moderate cases was 100% and that in severe cases was 45.5%. 2. In Group II pneumonia included 16 severe cases and 2 moderate cases with a mean age of 68.2 years. Significant underlying diseases were present in 15 out of 18 (83.3%, all of the underlying diseases were pulmonary diseases) and the overall efficacy rate was 72.2% with 100% efficacy rate among moderate cases and 68.8% among severe cases. 3. In the cases with chronic respiratory tract infections caused by P. aeruginosa, the efficacy rate was 82.6% and the eradication rate was 65.2%. We consider the combination therapy of CAZ and TOB is useful for intractable pulmonary infections caused by P. aeruginosa.

[Diagnosis of pulmonary tuberculosis in general hospital "a study of 114 cases"].

We conducted a study on the diagnosis of pulmonary tuberculosis at Chiba Kaihin Municipal Hospital. Examinations were performed to determine the presence of active Mycobacterium tuberculosis in sputum and gastric aspirate. For the sputum smear-negative cases, fiberoptic bronchoscopy was further used as a means for detecting the tuberculosis. The results obtained were as follows: 1. A total of 114 cases in the past six years diagnosed as active pulmonary tuberculosis (including 88 primary treatment cases) were analysed. 2. The 114 cases consisted of 74 males and 40 females, the mean age was 49.3 years old. Categorically, the main age groups were: 60s, 24 cases; 30s, 21 cases; and 40s, 20 cases. 3. Chest X-ray findings: Cavitary cases were 28.9% GAKKAI classification of the sizes of the affected areas being Type 1 (mostly limited cases), 58.9% of all total cases, and 68.4% in the cases under the age of 50 years old. The number of cases having infection in a solitary nodule was 19, and the ages of 15 out of the 19 patients were under 50 years old. 4. Sputum or gastric aspirate smear-positive cases totalled 37 (32.5%), and culture-positive cases totalled 77 (67.5%). Sputum or gastric aspirate cultures were positive in 52 out of 56 cases (92.9%) with extended shadows, GAKKAI classification Types 2 and 3, but were positive in 25 out of 58 cases (43.1%) with Type 1. 5. Fiberoptic bronchoscopy was performed on 49 out of the 77 smear-negative cases. 6. Definite diagnosis was obtained in 90 (78.8%) out of total 114 cases. The results of this study suggest that examination for active mycobacterium in sputum and gastric aspirate are very useful for the diagnosis of active pulmonary tuberculosis, especially in extended cases.

[Clinical evaluation of therapy for aspiration pneumonia with imipenem/cilastatin sodium].

In an open, prospective, multicenter trial the clinical efficacy of imipenem/cilastatin sodium (IPM/CS) for the treatment of 14 cases with aspiration pneumonia was investigated. The mean age was 75.4 years old. Diseases of central nervous system were present in 11 cases, cardiovascular diseases, pulmonary diseases and diabetes mellitus in 2 cases each respectively. Seven cases were community-acquired and another seven were hospital-acquired. Six cases were moderate and 8 cases were severe. Causative organisms were determined in 9 cases (64.3%), multiple causative organisms were isolated in 3 cases. Isolated organisms were Staphylococcus aureus (4), Pseudomonas aeruginosa (3), Klebsiella pneumoniae (3), Escherichia coli (1), Acinetobacter calcoaceticus (1). Detection of anaerobes was not attempted. Clinical effects of IPM/CS were excellent in 3, good in 8, fair in 2, poor in 1, the efficacy rate was thus 78.6%. P. aeruginosa was isolated from 2 out of 3 cases in which therapy with IPM/CS failed. Monotherapy with IPM/CS appears to be highly effective for cases of aspiration pneumonia, but the disease due to IPM-resistant P. aeruginosa is an exception.

[Clinical evaluations of ofloxacin in the treatment of Mycoplasma pneumoniae pneumonia in adults].

We studied the clinical efficacy of ofloxacin (OFLX) in the treatment of 13 cases of Mycoplasma pneumoniae pneumonia. OFLX was given to each patient orally at 200 mg/dose, 3 doses daily. One case was excluded because of a side effect i.e., nausea. In 12 evaluable cases, the clinical efficacy rate was 100% i.e., excellent in 7, good in 5. OFLX is one of the useful drugs in the treatment of M. pneumoniae pneumonia.

[Community acquired pulmonary infections in a general hospital].

We studied community acquired pulmonary infections in general hospital. Forty-seven outpatients (group I) and 107 inpatients (group II) were analyzed respectively. The mean age of group I was 43.4 years old and that of group II was 57.4 years old. Significant underlying diseases were present in 45% of group I and 62% of group II. In group I, the underlying diseases were chronic respiratory diseases, and in group II, chronic respiratory diseases and other significant diseases such as diabetes mellitus, cardiovascular diseases, malnutrition or malignancy. All of group I and 81 cases of group II were pneumonia. Pleuritis with pneumonia (11), lung abscess or cavitary infection (11), and pyothorax (4) were included in group II. Etiologic organisms were determined in 48.6% of the cases in group I, and 44.0% in group II. Invasive methods such as transtracheal aspiration and percutaneous lung puncture aspiration were very useful for isolation of the pathogen. The pathogens isolated included H. influenzae (17), S. pneumoniae (10), M. pneumoniae (4), C. psittaci (4) in total cases. In group I, H. influenzae was mostly isolated and in group II, S. pneumoniae was mostly isolated and opportunistic pathogens were also isolated. The form of pneumococcal pneumonia was almost always focal pneumonia in this study. There were 8 fatalities (5.2%), all of which were very old or had other serious diseases.